In the practice of storing or transporting fuel for later use, fuel can be lost to evaporation or spillage. When fuel escapes from its container, it is not only an economic loss but is also an environmental issue.
Fuel is typically stored and transported in rigid tanks, such as metal or rigid composite tanks. The metal tanks can corrode and leak liquid fuel or fuel vapors. Composite tanks can crack or delaminate and leak liquid fuel or fuel vapors. Moreover, rigid storage tanks are not collapsible and storable when not in use.
Thermoplastic polyurethanes (TPU) are known to be very abrasion resistant and easily processed by extrusion or calendering into sheet or film forms. Typical TPU polymers are not normally suitable for storing large amounts of fuel because they are not resistant to the passage of fuel vapors. Also, thermoplastic polymers tend to build up static electrical charges when fuel moves around in contact with the thermoplastic. The movement of the fuel occurs when the storage device is filled or emptied with fuel. A static charge around fuel can be very hazardous. A small discharge of static electricity can cause an explosion and fire to occur.
Patent Application WO 2010/017744A1 describes a membrane which can be inserted in a normal rigid fuel storage tank. The membrane has a layer of anti-static material on the inside (next to the fuel), a gas barrier layer and an outer layer that is resistant to wear and tear.
There is a need for a fuel storage membrane which will dissipate static electrical charges, is resistant to dissolving in the fuel, is resistant to the passage of fuel vapors and is easily storable when not in use.